Apparatus for tinning of metal wire

ABSTRACT

Apparatus for tinning of metal wire, particularly copper wire, at a high running speed. The apparatus has a trough filled with a tin bath and is provided on two oppositely positioned side surfaces with openings which are arranged coaxially to one another and through which the wire is guided into or out of the bath. The axis of said openings is eccentric with respect to the central axis of the trough and means pivot said trough about the axis of the openings to selectively effect immersion, or removal therefrom, of the wire.

United States Patent n 1 Stoiber [451March 20, 1973 [54] APPARATUS FOR TINNING OF METAL WIRE [75] Inventor: Siegfried Stoiber, A-4020 Linz, Austria [73] Assignee: Firma Gebauer & Griller, Vienna,

Austria [22] Filed: Dec. 3, 1970 [21] Appl. No.: 94,904

[52] US. Cl ..118/405, 118/425 [51] Int. Cl ..B05c 3/12 [58] Field of Search ......118/404, 405, 429, 421, 425, l18/D1G. 18,D1G. 19; 117/114 A, 114,.114

B, 114 C, 115; 266/4 A; 164/275 5 6 References Cited 2,111,853 3/1938 Fourness et a1 ..118/405 X 2,199,067 4/ 1940 Bradt ..1 18/405 X 2,393,678 1/1946 Graham 118/DlG. 18 2,405,221 8/1946 Mann ..118/405 X 2,507,310 5/1950 Lodge ..118/405 3,060,056 10/1962 Scott ..1 18/405 X 2,834,692 5/1958 Tama ..118/405 X FOREIGN PATENTS OR APPLICATIONS 1,066,832 10/1959 Germany ..117/114 B 839,556 6/1960 Great Britain .l ..164/275 Primary Examiner-Morris Kaplan Attorney-Woodhams, Blanchard & Flynn [57] ABSTRACT 1 Claim, 9 Drawing Figures PATENTEUmzoma SHEET 30F 5 m DI 1 APPARATUS FOR TINNING OF METAL WIRE The invention relates to an apparatus for tinning metal wire, particularly copper wire, at a high running speed, which apparatus comprises a trough filled with a tin bath.

In known apparatus for tinning metal wire, a trough filled with a tin bath is provided, which trough is provided with a return guide, for example -a roller, in the tin bath. During tinning of the wire, the wire is pulled through the tin bath and the wire passes around the return guide. Such known apparatus have a disadvantage in that a layer of oxide is formed on the upper surface of the tin bath through which the metal wire is guided. Thus, the wire, during its entrance into the tin bath and also during its exit from the tin bath, passes through the oxide layer so that the-quality of the tin coating on the wire is affected. If the return guide is a roller, the tin bath is moved or stirred considerably by the rotation of the roller so that .the amount of the oxide film on the surface of the tin bath is increased.

A further disadvantage of such known apparatus is I gastight enclosure so that the tin bath can be under a vacuum or a protective nonoxidizing gas can be present whereby, on the one hand, oxidation of the tin on the upper surface of the bath is mostly-avoided and, on the that the return movement of the wire in the tin bath 7 limits the speed at which the wire can be pulled through the tin bath to a certain maximum value due to the ridigity of the wire. Since copper is soluble in tin, the tin bath is enriched by dissolved copper and must therefore 'be replaced or treated from time to time to reduce the copper content thereof. If one is successful in reducing the amount of copperdissolved in the tin bath by increasing the speed at which the copper wire is moved through the tin bath, a greater amount of copper wire can be tinned with-a predetermined amount of a tin bath. Thus,,i t is desirable to increase the speed at which. the copper wire is guided through the tin bath.

Finally, known apparatus which are'provided with a return guide for the wire in the tin bath have the disadtioned side surfaces with openings which are arranged coaxially with one another. The wire is'guided into and out of the bath through these openings. Thus, the apparatusof the invention does not require a return guide for the wire and, therefore, the speed at which the wire is guided through the tin bath can be increased and, further, no uneveness in the tinning occurs. Furthermore, the wire also does not need to pass through the upper surface of the tin bath so that a reduction in the quality of the tin coating, due to oxides, 'is avoided. Finally, an apparatus according to the invention can be combined directly with a pulling machine and, thus, the wire can be guided through the tin'bath at the same speed at which it is pulled.

, The trough is advantageously provided with dies which are positioned coaxially to one another at two oppositely positioned front surfaces. These dies are advantageously heated in order to avoid hardening of the tin in the drawing dies. In order to easily introduce'the other hand, a-splashing of the tin is impossible, e.g. 'as by preventing leakage through the dies by maintaining .the tin bath under such a vacuum.

In an installation according to the invention for warm tinning of a wire, particularly a copper wire, which apparatus consists of a pulling device, an annealing device, a device for preparing the wire for tinning, a tinning apparatus and a cooling device, the device for preparing the wire for tinning, the tinning apparatus and the cooling device can be arranged one following the other and aligned in the pulling direction ofthe wire so that no return or reverse movement of the wire is required and, as mentioned, a high speed movement of the wire through these devices is possible. An apparatus according to the invention will be .discussed in detail'hereinafter 'in fconnection with one tinning of wire,

FIGS. 2 and 2a are partially sectioned front and side views of an apparatus for tinning of a' wire, the apparatus being in the position in which the front end of the wire can be introduced into said apparatus,

FIGS. 3 and 3a are corresponding front and side views of said apparatus with the parts in their operating positions.

FIGS.- 4 and 4a are a partially cross-sectional side view and a top view of a rapid-locking device for fixing a die on the front surface of the trough-of the apparatus for tinning,

FIG. 5 is a front view of an apparatus for the preparation of the wire for the tinning, and

FIG. 6 is a front view of a cooling device.

7 The system for the warm tinning of wire which is illustrated in FIG. 1 consists of a storage spool 1 onto which a forwardly pulled wire having a diameter of, for example, 2.5 mm. is wound. Following this apparatusa pulling machine 2, an annealing device 3, a cleaning device 4, a vacuum tinning apparatus 5, a cooling device 6 and a wind-up device 7 are arranged in that order in the pulling direction. During the operation of the apparatus, .the wire is pulled off from the storage spool l and is thereafter pulled to a diameter of 0.8 mm., treated with a flow means, tinned and cooled or dried and finally-wound up on the spool device 7.

The apparatus 5 for warm tinning the wire which is illustrated in FIGS. 2 to 3a consists of a frame 10 which carries an elongated cylindrical trough 11 which is supported for pivotal movement about an axis which is parallel to its longitudinal axis. An opening in the trough 11 for the purpose of introducing a tin 'bath into said trough is sealed in a gas-tight fashion by a lid 13.

Furthermore, the trough is provided with a heater by means of which the tin bath 14 can be heated to the required operating temperature or can be maintained at said temperature.

The swinging of the trough 1 l is effected by means of a crank arm 17 and a hinged arm 18 which is hingedly connected to a bracket 19 on the trough l 1. The crank arm 17 can be swung by a motor 16.

A die 20 which is heated by a heater 26 is arranged on the end wall of the trough 11 as can be seen in FIGS. 4 and 4a. A corresponding die is arranged on the opposite end wall of the trough. The die can be releasably fixed in its position by means of a rapid-locking device which is formed by a pivotable lever 22 and a wing nut 24 cooperating with a threaded member 23. A sleeve 25 is interpositioned between the lever 22 and the die 20.

The motor 16 which is used for swinging the crank arm 17 and parts of a cooling device 28 and also a device 29 for evacuating the trough 11 are arranged below the trough 11 in the frame 10.

As can be seen from the drawings, the drawing dies 20 through which the wire 8, which is to be tinned, is guided are in a first position of the trough 11 (FIGS. 2,2a) above-the level of the tin bath 14 so that the dies can be removed from thefront wall of the trough and so that the front end of the wire 8 can be guided through the right drawing die into the trough 11 and through the'left drawing die out of the trough. When the tinning apparatus is to be used, the trough 11 is pivoted about its axis so that the drawing dies are moved to positions below the upper surface of the tin bath 14 (FIGS. 3,3a) so that the wire 8 canbe guided through said tin bath 14. As can be taken from this, not only is the wire thus guided rectilinearly through the tin bath but also a contact of the wire with the surface of the tin bath on which an oxide film may be present is also avoided.

In order to also possibly protect the tin bath against oxidation, a vacuum can be maintained in the trough above the tin bath or a protective nonoxidizing gas can be present. The maintaining of an inert gas is advanta'geous also because the amount of externally supplied heat to maintain the temperature required for the tinning is reduced.

The device for preparing the wire for tinning, illustrated in FIG. 5, consists of a frame 30 which has a tank 31 filled with flux means. Felt pieces 32 are mounted in' said tank, through which felt pieces the wire 8 can be guided and thus is intensively wetted with the flux means. In order to wipe the excess flux means off the wire 8, a scraping stone 34 and a felt wiper 35 are arranged in direction of movement of the wire behind the tank 31. The excess flux means wiped off through these parts reaches a collecting basin 36 from where it is led into a container 37 which is connected to the tank 31 through a pump 39 and line 38.

The cooling and drying device consists of a frame 40 which carries a tank 41 filled with a cooling fluid, through which tank the wire 8 can be guided, and a device 42 for drying the wire by means of air. The tank 41 is supplied with cooling fluid through a line 44. The cooling fluid reaches a collecting basin 45 and is discharged through a line 46. The device 42 for drying by air is supplied through a line 47 in which the necessary valves, pressure controls, etc. are arranged.

thick layers where the layer of tin has a thickness of for example 5 1.. For this purpose it is required only to exchange the dies 20 with dies having enlarged openings.

As should be understood from the above discussion of the apparatus of the invention, a special advantage is that the wire to be tinned can be pulled rectilinearly through the apparatus for tinning and also through the further apparatus arranged behind or in front of said apparatus, through which, due to the increased speed at which the wire can be moved, on the one hand, the capacity of the entire installation is increased compared with known installations and furthermore the tin bath does not require regeneration as often as is the case in comparable known apparatus. Finally the wire to be tinned is not guided through the upper surface of the tin bath which assures a better quality of tinning.

I claim: 1. Apparatus for metallizing of metal wire at a high running speed comprising:

a trough containing a molten metal bath, and said I trough having two oppositely positioned end surfaces with openings arranged coaxially to one another below theoperating level of the-surface of said molten metalbathj I means for closing the trough gas tight;

dies at said openings through which the wire is guided into and out of the bath;

said dies being releasable from. said surfaces of the trough to thus permit a pulling-in of the wire and includinga rapid locking devide for fixing said dies in position on said trough;

said rapid locking device comprising a pivotal leve onsaid trough surface and a threaded connector including a nut engaging said lever and tightenable to positively hold said lever overlying said die to maintain said die fixed at said opening, said lever being configured to allow linear passage of said wire therepast and a sleeve interposed between said die and lever and through which said wire passes; means on said trough for heating said bath to maintain same at a required temperature, said trough being of elongated cylindrical form and said heating means being on the side wall of said trough;

local means for heating said dies comprising a pair of local heaters each mounted on an end of said trough in close and heat transmitting adjacency with a corresponding one of said dies;

said trough including coaxial pivot means at the opposite ends of said trough coaxial with said openings and eccentric of the central axis of said trough, the surface of the molten metal being below the axes of pivot means and said dies in one pivotal position of the trough and above said axes of said pivot means and said diesin another position of said trough means connected to said trough for maintaining a vacuum over the surface of said bath;

whereby local heating of said dies maintains said molten metal fluid in the region of said dies to prevent buildup of both metal in said dies and said vacuum maintaining means tends to prevent leakage of molten bath metal through said dies by providing an inward pressure drop across said dies. 

1. Apparatus for metallizing of metal wire at a high running speed comprising: a trough containing a molten metal bath, and said trough having two oppositely positioned end surfaces with openings arranged coaxially to one another below the operating level of the surface of said molten metal bath; means for closing the trough gas tight; dies at said openings through which the wire is guided into and out of the bath; said dies being releasable from said surfaces of the trough to thus permit a pulling-in of the wire and including a rapid locking devide for fixing said dies in position on said trough; said rapid locking device comprising a pivotal lever on said trough surface and a threaded connector including a nut engaging said lever and tightenable to positively hold said lever overlying said die to maintain said die fixed at said opening, said lever being configured to allow linear passage of said wire therepast and a sleeve interposed between said die and lever and through which said wire passes; means on said trough for heating said bath to maintain same at a required temperature, said trough being of elongated cylindrical form and said heating means being on the side wall of said trough; local means for heating said dies comprising a pair of local heaters each mounted on an end of said trough in close and heat transmitting adjacency with a corresponding one of said dies; said trough including coaxial pivot means at the opposite ends of said trough coaxial with said openings and eccentric of the central axis of said trough, the surface of the molten metal being below the axes of pivot means and said dies in one pivotal position of the trough and above said axes of said pivot means and said dies in another position of said trough means connected to said trough for maintaining a vacuum over the surface of said bath; whereby local heating of said dies maintains said molten metal fluid in the region of said dies to prevent buildup of both metal in said dies and said vacuum maintaining means tends to prevent leakage of molten bath metal through said dies by providing an inward pressure drop across said dies. 